Red alert prompts fresh warning to water users at Burrendong and Windamere Dams

Recreational water users are warned to take a high alert for blue green algae seriously and not enter Burrendong and Windamere Dams.

The red alert was introduced at the end of last month when routine monitoring detected high numbers of the potentially toxic bacteria.

Some waterskiiers have since suffered infections.

Vicki Martin from the Central West Algal Coordinating Committee says people should assume any algae is toxic.

"Some algae will have allergens on the external surfaces of their cells and that will give rise to things like skin and eye irritations, in terms of the toxins, the toxins are produced when the algae gets stressed and those sorts of things can cause stomach upsets and further problems," she said.

Ms Martin says they should avoid areas where scum is visible.

"If people see anything that looks like a paint poured over the water then I would definitely avoid that because that's a very thick scum and sometimes it can be seen if a clear container is dipped into the water then you might see clear flecks, it also sometimes has a bit of a musty odour about it."